Image sensor test system including operational amplifier and low-frequency attenuator

Abstract

An image sensor test system includes a test device configured to transmit an input signal and a control signal to at least one image sensor through a probe card, and an interface board configured to map the probe card and the test device to each other. The interface board includes a signal receiver configured to receive an image signal from the at least one image sensor, amplify the image signal, and output the image signal to the test device, and the signal receiver includes an operational amplifier configured to amplify the image signal, and a low-frequency attenuator connected to an output terminal of the operational amplifier.

What is claimed is: 
     
       1. An image sensor test system comprising:
 a test device configured to transmit an input signal and a control signal to at least one image sensor through a probe card; and 
 an interface board configured to map the probe card and the test device to each other, 
 wherein the interface board comprises a signal receiver configured to receive an image signal from the at least one image sensor, amplify the image signal, and output the image signal to the test device, and 
 wherein the signal receiver comprises:
 an operational amplifier configured to amplify the image signal, 
 a low-frequency attenuator connected to an output terminal of the operational amplifier, and 
 a first comparator, a second comparator, and a third comparator, 
 
 wherein the second comparator is connected to an output terminal of the low-frequency attenuator, 
 wherein the first comparator and the third comparator are configured to operate in a low-power mode, and 
 wherein the second comparator is configured to operate in a high-speed operation mode. 
 
     
     
       2. The image sensor test system of  claim 1 , wherein the interface board further comprises a mobile industry processor interface (MIPI) D-PHY configured to communicate with the test device based on a MIPI. 
     
     
       3. The image sensor test system of  claim 1 , wherein the low-frequency attenuator comprises:
 a resistor element; and 
 a capacitor element connected to the resistor element in parallel. 
 
     
     
       4. The image sensor test system of  claim 3 , wherein each of the operational amplifier, the resistor element, and the capacitor element comprises a discrete device. 
     
     
       5. The image sensor test system of  claim 1 , wherein the signal receiver further comprises:
 a first branch resistor and a second branch resistor branching from an input terminal of the operational amplifier; 
 wherein the first comparator comprises a first input terminal to which the first branch resistor is connected, and 
 wherein the third comparator comprises a second input terminal to which the second branch resistor is connected. 
 
     
     
       6. The image sensor test system of  claim 1 , wherein the operational amplifier comprises a differential amplifier. 
     
     
       7. The image sensor test system of  claim 6 , wherein the test device comprises:
 an image signal analyzer configured to receive the image signal transmitted from the signal receiver, and output image data; and 
 an image data transmitter configured to transmit the image data output from the image signal analyzer to an processing device. 
 
     
     
       8. The image sensor test system of  claim 7 , wherein the processing device is configured to convert the image data transmitted from the image data transmitter into a two-dimensional image, and determine a pass or a failure of the at least one image sensor. 
     
     
       9. The image sensor test system of  claim 1 , wherein the test device is implemented as a field programmable gate array (FPGA). 
     
     
       10. An image sensor test system comprising:
 a probe card comprising a probe contacting at least one image sensor; 
 a test device configured to transmit input and control signals to the at least one image sensor through the probe card; and 
 an interface board configured to map the probe card and the test device to each other, 
 wherein the interface board comprises a signal receiver configured to:
 receive an image signal from the at least one image sensor, 
 amplify the image signal; and 
 output the image signal to the test device, and 
 
 wherein the signal receiver comprises:
 an operational amplifier configured to amplify the image signal, 
 a low-frequency attenuator connected to at least one of an input terminal and an output terminal of the operational amplifier, and 
 a first comparator, a second comparator, and a third comparator, 
 
 wherein the second comparator is connected to an output terminal of the low-frequency attenuator, 
 wherein the first comparator and the third comparator are configured to operate in a low-power mode, and 
 wherein the second comparator is configured to operate in a high-speed operation mode. 
 
     
     
       11. The image sensor test system of  claim 10 , wherein the test device further comprises a light source configured to emit light to the at least one image sensor, and
 wherein the signal receiver is configured to transmit the image signal output from the at least one image sensor to the test device in response to the light emitted from the light source. 
 
     
     
       12. The image sensor test system of  claim 10 , wherein the signal receiver further comprises:
 a first branch resistor and a second branch resistor branching from an input terminal of the operational amplifier; 
 wherein the first comparator comprises a first input terminal to which the first branch resistor is connected, and 
 wherein the third comparator comprises a second input terminal to which the second branch resistor is connected. 
 
     
     
       13. The image sensor test system of  claim 10 , wherein the low-frequency attenuator comprises a first low-frequency attenuator and a second low-frequency attenuator connected to the output terminal of the operational amplifier,
 wherein the first low-frequency attenuator comprises a first resistor element and a first capacitor element connected to the first resistor element in parallel, 
 wherein the second low-frequency attenuator comprises a second resistor element and a second capacitor element connected to the second resistor element in parallel, 
 wherein the first resistor element and the second resistor element have the same resistance, and 
 wherein the first capacitor element and the second capacitor element have the same capacitance. 
 
     
     
       14. The image sensor test system of  claim 13 , wherein each of the operational amplifier, the first resistor element, the second resistor element, the first capacitor element and the second capacitor element comprises a discrete device. 
     
     
       15. An image sensor test system comprising:
 a probe card comprising a probe contacting at least one image sensor; 
 a test device configured to transmit input and control signals to the at least one image sensor through the probe card; and 
 an interface board configured to map the probe card and the test device to each other, the interface board comprising a mobile industry processor interface (MIPI) D-PHY configured to communicate with the test device based on a MIPI, 
 wherein the interface board further comprises a signal receiver configured to:
 receive an image signal from the at least one image sensor, 
 amplify the image signal, and 
 output the image signal to the test device, and 
 
 wherein the signal receiver comprises:
 an operational amplifier configured to amplify the image signal, 
 a low-frequency attenuator connected to at least one of an input terminal and an output terminal of the operational amplifier, the low-frequency attenuator comprising a resistor element and a capacitor element connected to the resistor element in parallel, and 
 a first comparator, a second comparator, and a third comparator, 
 
 wherein the second comparator is connected to an output terminal of the low-frequency attenuator, 
 wherein the first comparator and the third comparator are configured to operate in a low-power mode, and 
 wherein the second comparator is configured to operate in a high-speed operation mode. 
 
     
     
       16. The image sensor test system of  claim 15 , wherein the operational amplifier comprises a differential amplifier. 
     
     
       17. The image sensor test system of  claim 15 , wherein each of the operational amplifier, the resistor element, and the capacitor element comprises a discrete device. 
     
     
       18. The image sensor test system of  claim 15 , wherein the test device comprises:
 an image signal analyzer configured to receive the image signal transmitted from the at least one image sensor, and output image data; and 
 an image data transmitter configured to transmit the image data output from the image signal analyzer to a processing device.